1 /* 2 * Virtio 9p backend 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "hw/virtio/virtio.h" 16 #include "qemu/sockets.h" 17 #include "virtio-9p.h" 18 #include "fsdev/qemu-fsdev.h" 19 #include "coth.h" 20 #include "hw/virtio/virtio-access.h" 21 #include "qemu/iov.h" 22 23 static const struct V9fsTransport virtio_9p_transport; 24 25 static void virtio_9p_push_and_notify(V9fsPDU *pdu) 26 { 27 V9fsState *s = pdu->s; 28 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 29 VirtQueueElement *elem = v->elems[pdu->idx]; 30 31 /* push onto queue and notify */ 32 virtqueue_push(v->vq, elem, pdu->size); 33 g_free(elem); 34 v->elems[pdu->idx] = NULL; 35 36 /* FIXME: we should batch these completions */ 37 virtio_notify(VIRTIO_DEVICE(v), v->vq); 38 } 39 40 static void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq) 41 { 42 V9fsVirtioState *v = (V9fsVirtioState *)vdev; 43 V9fsState *s = &v->state; 44 V9fsPDU *pdu; 45 ssize_t len; 46 VirtQueueElement *elem; 47 48 while ((pdu = pdu_alloc(s))) { 49 P9MsgHeader out; 50 51 elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); 52 if (!elem) { 53 goto out_free_pdu; 54 } 55 56 if (elem->in_num == 0) { 57 virtio_error(vdev, 58 "The guest sent a VirtFS request without space for " 59 "the reply"); 60 goto out_free_req; 61 } 62 QEMU_BUILD_BUG_ON(sizeof(out) != 7); 63 64 v->elems[pdu->idx] = elem; 65 len = iov_to_buf(elem->out_sg, elem->out_num, 0, 66 &out, sizeof(out)); 67 if (len != sizeof(out)) { 68 virtio_error(vdev, "The guest sent a malformed VirtFS request: " 69 "header size is %zd, should be 7", len); 70 goto out_free_req; 71 } 72 73 pdu_submit(pdu, &out); 74 } 75 76 return; 77 78 out_free_req: 79 virtqueue_detach_element(vq, elem, 0); 80 g_free(elem); 81 out_free_pdu: 82 pdu_free(pdu); 83 } 84 85 static uint64_t virtio_9p_get_features(VirtIODevice *vdev, uint64_t features, 86 Error **errp) 87 { 88 virtio_add_feature(&features, VIRTIO_9P_MOUNT_TAG); 89 return features; 90 } 91 92 static void virtio_9p_get_config(VirtIODevice *vdev, uint8_t *config) 93 { 94 int len; 95 struct virtio_9p_config *cfg; 96 V9fsVirtioState *v = VIRTIO_9P(vdev); 97 V9fsState *s = &v->state; 98 99 len = strlen(s->tag); 100 cfg = g_malloc0(sizeof(struct virtio_9p_config) + len); 101 virtio_stw_p(vdev, &cfg->tag_len, len); 102 /* We don't copy the terminating null to config space */ 103 memcpy(cfg->tag, s->tag, len); 104 memcpy(config, cfg, v->config_size); 105 g_free(cfg); 106 } 107 108 static void virtio_9p_device_realize(DeviceState *dev, Error **errp) 109 { 110 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 111 V9fsVirtioState *v = VIRTIO_9P(dev); 112 V9fsState *s = &v->state; 113 114 if (v9fs_device_realize_common(s, errp)) { 115 goto out; 116 } 117 118 v->config_size = sizeof(struct virtio_9p_config) + strlen(s->fsconf.tag); 119 virtio_init(vdev, "virtio-9p", VIRTIO_ID_9P, v->config_size); 120 v->vq = virtio_add_queue(vdev, MAX_REQ, handle_9p_output); 121 v9fs_register_transport(s, &virtio_9p_transport); 122 123 out: 124 return; 125 } 126 127 static void virtio_9p_device_unrealize(DeviceState *dev, Error **errp) 128 { 129 VirtIODevice *vdev = VIRTIO_DEVICE(dev); 130 V9fsVirtioState *v = VIRTIO_9P(dev); 131 V9fsState *s = &v->state; 132 133 virtio_cleanup(vdev); 134 v9fs_device_unrealize_common(s, errp); 135 } 136 137 static void virtio_9p_reset(VirtIODevice *vdev) 138 { 139 V9fsVirtioState *v = (V9fsVirtioState *)vdev; 140 141 v9fs_reset(&v->state); 142 } 143 144 static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t offset, 145 const char *fmt, va_list ap) 146 { 147 V9fsState *s = pdu->s; 148 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 149 VirtQueueElement *elem = v->elems[pdu->idx]; 150 151 return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap); 152 } 153 154 static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset, 155 const char *fmt, va_list ap) 156 { 157 V9fsState *s = pdu->s; 158 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 159 VirtQueueElement *elem = v->elems[pdu->idx]; 160 161 return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap); 162 } 163 164 /* The size parameter is used by other transports. Do not drop it. */ 165 static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov, 166 unsigned int *pniov, size_t size) 167 { 168 V9fsState *s = pdu->s; 169 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 170 VirtQueueElement *elem = v->elems[pdu->idx]; 171 172 *piov = elem->in_sg; 173 *pniov = elem->in_num; 174 } 175 176 static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov, 177 unsigned int *pniov) 178 { 179 V9fsState *s = pdu->s; 180 V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); 181 VirtQueueElement *elem = v->elems[pdu->idx]; 182 183 *piov = elem->out_sg; 184 *pniov = elem->out_num; 185 } 186 187 static const struct V9fsTransport virtio_9p_transport = { 188 .pdu_vmarshal = virtio_pdu_vmarshal, 189 .pdu_vunmarshal = virtio_pdu_vunmarshal, 190 .init_in_iov_from_pdu = virtio_init_in_iov_from_pdu, 191 .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu, 192 .push_and_notify = virtio_9p_push_and_notify, 193 }; 194 195 /* virtio-9p device */ 196 197 static const VMStateDescription vmstate_virtio_9p = { 198 .name = "virtio-9p", 199 .minimum_version_id = 1, 200 .version_id = 1, 201 .fields = (VMStateField[]) { 202 VMSTATE_VIRTIO_DEVICE, 203 VMSTATE_END_OF_LIST() 204 }, 205 }; 206 207 static Property virtio_9p_properties[] = { 208 DEFINE_PROP_STRING("mount_tag", V9fsVirtioState, state.fsconf.tag), 209 DEFINE_PROP_STRING("fsdev", V9fsVirtioState, state.fsconf.fsdev_id), 210 DEFINE_PROP_END_OF_LIST(), 211 }; 212 213 static void virtio_9p_class_init(ObjectClass *klass, void *data) 214 { 215 DeviceClass *dc = DEVICE_CLASS(klass); 216 VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); 217 218 dc->props = virtio_9p_properties; 219 dc->vmsd = &vmstate_virtio_9p; 220 set_bit(DEVICE_CATEGORY_STORAGE, dc->categories); 221 vdc->realize = virtio_9p_device_realize; 222 vdc->unrealize = virtio_9p_device_unrealize; 223 vdc->get_features = virtio_9p_get_features; 224 vdc->get_config = virtio_9p_get_config; 225 vdc->reset = virtio_9p_reset; 226 } 227 228 static const TypeInfo virtio_device_info = { 229 .name = TYPE_VIRTIO_9P, 230 .parent = TYPE_VIRTIO_DEVICE, 231 .instance_size = sizeof(V9fsVirtioState), 232 .class_init = virtio_9p_class_init, 233 }; 234 235 static void virtio_9p_register_types(void) 236 { 237 type_register_static(&virtio_device_info); 238 } 239 240 type_init(virtio_9p_register_types) 241